


Surprises

by fuzipenguin



Category: The Transformers (IDW Generation One)
Genre: Demisexuality, Dom/sub Undertones, Established Relationship, Estrangement, Fade to Black, M/M, Multi, Open Relationships, Other, Propositions, Reunions, Twincest
Language: English
Status: Completed
Published: 2020-12-13
Updated: 2020-12-13
Packaged: 2021-03-11 00:20:08
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,706
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28056012
Author URL: https://archiveofourown.org/users/fuzipenguin/pseuds/fuzipenguin
Summary: Sunstreaker is pleasantly surprised when he reunites with Sideswipe on Cybertron... in more than one way.
Relationships: Rung/Sideswipe/Sunstreaker (Transformers), Sideswipe/Sunstreaker (Transformers)
Comments: 12
Kudos: 43





	Surprises

**Author's Note:**

> Written for a prompter who donated to my wife's surgery fund

“… and then Arcee… hey, who’s that?”

Sunstreaker startled when Sideswipe nudged his arm, and he refocused his attention on his brother. “Huh?”

Sideswipe smiled and pointed with his chin at the small figure looking around at the bottom of the Lost Light’s disembarking ramp. “That. Who’s that?”

“Oh. That’s Rung. He was on the ship with us. He’s one of Cybertron’s last psychoanalysts supposedly,” Sunstreaker said dismissively. “What did Arcee do next?”

“Nothing important. So a shrink, hm? Yours?” Sideswipe asked, turned slightly to observe Rung’s frame.

“What? No! Just a… a shipmate,” Sunstreaker said, because honestly, they had never interacted much. That was all their relationship could be called, when one boiled it down.

“Just a shipmate?” Sideswipe glanced over his shoulder with a raised orbital ridge. “But you’re interested in him?”

“… no.” ‘

‘Interested’ was a mild term for the way sometimes Sunstreaker couldn’t stop looking at Rung. There was something about him… but Sunstreaker had never acted on his fascination and it didn’t matter since he wasn’t continuing on with the Lost Light.

Sideswipe turned and fully faced Sunstreaker, staring him down. “Sunny… that’s not your disinterested face. That’s your ‘I’m intrigued’ face.”

“How would you know? You haven’t seen it in so long,” Sunstreaker snapped, starting to feel defensive.

Sideswipe’s lips pressed together and he in-vented deeply while Sunstreaker internally berated himself. Twenty minutes. Not even twenty minutes and he was already falling back into old habits.

“I’m sorry,” Sunstreaker said contritely. “That was uncalled for; you of all people actually would know pretty well.”

“You’re forgiven. Besides, you’re not entirely wrong. But _am_ I at least partially right about this guy?” Sideswipe asked after a moment.

Sunstreaker shifted from one foot to the other, watching Rung chat amicably with Rewind and Chromedome. “… yes.”

“Wanna do something about it?” Sideswipe asked, tilting his head towards Rung. “Proposition him at least?” 

Sunstreaker blinked at his brother. “Just because I’m intrigued doesn’t mean I want to ‘face him. I… he’s nice and never seemed to care about anything I’ve done. Of course, Whirl was his patient, so I guess I kind of pale in comparison.”

Sideswipe made a face. “Ugh, that guy. Even _I_ think he’s an asshole.”

“That you are _definitely_ right about,” Sunstreaker said. The two of them shifted so that they stood side by side and watched as Rung started to amble off.

“Seriously, though,” Sideswipe said when Rung was about four ships away. “Do you want that?”

Sunstreaker looked at his brother askance. “You could share?”

It was a valid question; Sideswipe’s possessiveness had always been a point of contention between them.

Sideswipe looked over at him and gestured to himself. “I told you – new and improved brother, at your service. I’m certainly not going to be perfect, but I mean it when I said I want to be better to you. Besides, you’re staying, right? And he’s continuing on?”

“I don’t think Rung has any plans on leaving the ship. And yes, I’m staying,” Sunstreaker replied without any hesitation. “I’ve missed Cybertron, especially now that it’s built back up. And… I’ve missed you.”

The admission was worth it to see the shy smile that bloomed across Sideswipe’s face. “Well then… I can definitely share at least for a little bit.”

“I don’t know…” Sunstreaker said, then hurried to continue when he saw Sideswipe’s hurt expression. “No, not you; I believe you. I just don’t know if I want to do a one night stand type of thing right now. I mean… I like him. He’s cute and he’s really nice, I just… ”

“How about this? We follow him for a bit; I want to show you some of the sights and we might as well pick the direction he’s going in. If you change your mind along the way, we’ll approach him, ok?” Sideswipe offered.

Sunstreaker nibbled his bottom lip while glancing back at the ship. Rodimus had announced that the Lost Light would be docked for at least a week to stock up on supplies and to rotate the staff through leave. Bob was secure in their quarters and had been recently fed so he could keep for an evening if need be. Ratchet was on duty through until the morning, so Sunstreaker could also comm him to ask him to check in on the Insecticon if something did end up happening.

“Ok,” Sunstreaker said, slowly nodding. “Let’s do that.”

“Awesome!” Sideswipe beamed at him and reached for Sunstreaker’s hand. If possible, his smile got even bigger when Sunstreaker threaded their fingers together without hesitation. Sunstreaker’s spark warmed at the expression and he followed as Sideswipe led them away.

\--

“… huh.”

Sunstreaker looked at the storefront that Sideswipe was staring at, puzzled at his brother’s expression of surprise. “What? What is it?”

“Ok, well, he’s a little nerdy looking, so I didn’t blink at the hobby shop and the storystore. And lots of mecha have a sweet teeth, so the candy didn’t surprise me. Although the sheer amount seemed a lot for a bot his size. Anyway… I just didn’t expect him to go in there,” Sideswipe said, resting his hand on one cocked out hip.

“I don’t get it,” Sunstreaker said, looking from the store to Sideswipe and back again. “It’s a repair shop.”

Sideswipe shook his head. “That’s what the sign says, yes. And if you go in the front door, that’s the service you’ll get. But the door _he_ went into? That gets you a different kind of service.”

“Stop being cryptic, Sides,” Sunstreaker said in exasperation. “What kind of place is it?”

“The back half of the building is a BDSM club,” Sideswipe replied, looking at him. “And I don’t think he’s lost. He seemed to know where he’s going.”

“… oh.”

“Yeah, _oh_ ,” Sideswipe said. “You want to follow him in?”

Sunstreaker blinked at the store a few times trying to decide. “Uh, sure. If nothing else, we could have a few drinks, right?”

Sideswipe nodded absently. “They do make a delicious Cybertail. Alright, let’s go!”

“So you’ve been here before then?” Sunstreaker asked, feeling a little possessiveness of his own stir deep in his belly. Sideswipe smirked at him over his shoulder as they neared the door.

“A few times. I met a guy at work who wanted an introduction to the scene,” Sideswipe said. “I didn’t partake myself; I haven’t played with anyone since you left.”

Sunstreaker nodded in satisfaction and paused once inside to let his optics adjust to the dim lighting. They were in a dark hallway and Sunstreaker could hear the muffled thump of music from close by.

“That’s… that’s nice of you,” Sunstreaker said lamely, trying to think of a way to say that he was relieved his brother hadn’t partnered up with anyone for dominance play while they had been separated. He was sure Sideswipe had picked up mechs here and there for regular interfacing, but a scene between the two of them had always been special.

“What can I say? I’m a good citizen,” Sideswipe replied. “Oh, it’s busy tonight.”

They emerged into a large, cavernous room, dotted with tables and booths at the outer circumference. In the center was a dance floor where a few dozen mechs were gyrating, grooving to the beats the DJ at the far end of the room was putting out. Sideswipe led them over to an empty booth, flagging down one of the waitstaff as they passed by. As Sunstreaker settled, Sideswipe gave the waiter an order for several drinks, enough that Sunstreaker raised an orbital ridge when Sideswipe turned back to him.

“Just getting a sampling for you to try,” Sideswipe explained. “They don’t have a printed menu or anything. Got some snacks too; not sure when you fueled last.”

“This morning,” Sunsteaker said, realizing that he was a bit peckish. They had strolled a fair distance from the Lost Light, and it was starting to get late. “I see Rung over by the bar.”

“Yeah, I noticed that. What do you think he likes?” Sideswipe asked, slumping down next to Sunstreaker and leaning into his shoulder. Sunstreaker stiffened for a nanosecond before relaxing against him, catching a whiff of an unfamiliar but pleasant wax.

“I couldn’t even hazard a guess,” Sunstreaker said truthfully. “He’s got such a mild personality I assumed he’d be pretty vanilla. Even when I thought that though, I think I sort of wanted him.”

“So does this make you want him more or less?” Sideswipe asked. He turned his head and nuzzled Sunstreaker’s arm, placing a kiss on his plating. The dermal receptors tingled after Sideswipe’s lips had lifted away and Sunstreaker had to suppress a shiver at the loss.

“… more.”

“Mm. Thought it might. I bet he tops. Something in the way he holds himself maybe clued you in instinctively,” Sideswipe mused, gaze focused on Rung as he hopped onto a stool and spoke to the bartender. Sunstreaker imagined it, that tiny frame standing over him and giving him instruction. This time, he couldn’t stop the shiver.

“And you’d still be ok with it?” Sunstreaker asked, feeling a little trepidation because now he allowed himself to realize just how much he wanted Rung. He glanced down at his brother, meeting his optics when he turned his head.

“Yeah. I wouldn’t want to submit to a total stranger, even one you trusted, but I think it’d be hot to watch you with him. And he could be a little buffer between us until we ease back into things,” Sideswipe said. Sunstreaker searched his face, but could find no hint of anything but the truth. So at least Sideswipe believed that when he said it.

“… ok.”

Just then, their drinks arrived, and the two of them proceeded to taste test them all, Sideswipe pulling out a small data pad and writing down some notes. Sideswipe had always had an interest in cooking, and it seemed as if he had gotten back into it. Sunstreaker was happy to see that his twin had allowed himself hobbies; he had been a little worried that Sideswipe wouldn’t know what to do after the war had ended but he seemed content and healthy.

The two of them chatted amicably for at least an hour. Sunstreaker had dozens of stories about the shenanigans on the Lost Light, and Sideswipe had met a lot of interesting people while bodyguarding a local politician. When things occasionally neared previously touchy subjects, Sideswipe deftly directed them away to other topics.

Sunstreaker was grateful for it. Things felt good between them. There was no resentment or anger, just the familiar playful banter and comradery from their earlier years. As the drinks were consumed, Sideswipe moved closer and closer until he suddenly leaned forward and pressed a kiss to Sunstreaker’s lips in between swallows.

A little surprised, Sunstreaker froze for a split second, which was apparently long enough for Sideswipe to take it the wrong way.

“I’m sorry, I just…” Sideswipe looked apologetic and a little bit wary.

“No, no, it’s fine. Surprised me, is all,” Sunstreaker said and reached up a hand to cup Sideswipe’s nape. He pulled him in and their lips met again, moving against one another in a new yet old dance.

Despite the distance and time that had separated them, neither one of them seemed to be in a rush. They just re-explored each other’s mouths over the next several minutes, hands gently roaming each other’s plating. When Sideswipe pulled away again, he had a slightly regretful look on his face as he licked his lips, but a moment later, it turned determined.

“I want to do something nice for you. Let me go ask him?” Sideswipe asked in a husky tone of voice, tilting his head back towards the bar. “If we don’t reach out soon, I think he might either leave or get snatched up. I saw a few mechs checking him out.”

Sunstreaker looked over at Rung and then nodded. “Um. Yeah. But if he says ‘no’…”

“Then at least we tried. And we’ll do whatever you want from there,” Sideswipe said, pushing himself out of the booth. He grabbed several of their empty cups and blew Sunstreaker a kiss. “I’ll be back.”

Sunstreaker watched his brother make his way across the room, skirting the edge of the massive crowd on the dance floor. Now that it was a little later in the evening, there were several more mecha milling around than had been there earlier. Several of them wore neck collars and more than a few booths contained partners who were also kissing and groping one another.

Sideswipe got several admiring looks as he traversed the distance between their booth and the bar, but he didn’t pay any of them any attention… other than to gently remove a few hands that attached themselves to his aft in passing.

Moving nonchalantly, Sideswipe placed the empty glasses on the bar next to Rung and leaned in, brushing the doctor’s shoulder with two fingers to catch his attention. Sunstreaker watched Rung look up, the brighter lights above the bar reflecting off his glasses and obscuring his optics.

Sideswipe turned and pointed in Sunstreaker’s direction as they started conversing. Rung startled, his head swiveling towards Sunstreaker. Before Sunstreaker could do anything but sit up a little straighter, Rung looked back at Sideswipe and leaned in, the two of them talking quietly to one another.

Fretting a little, Sunstreaker fiddled with the edge of a glass, worried. What were they talking about? He hoped Sideswipe wasn’t pushing. Even though Sunstreaker was leaving the Lost Light and they likely wouldn’t see each other for a long time, he still didn’t want Rung to be persuaded into anything he didn’t really want to do.

And Sideswipe could be awfully persuasive when he wanted to be.

Finally, after another minute or two of talking, Rung swallowed the last of his drink and placed the glass on the bar. When Sideswipe held out his hand, Rung took it and used it as support to clamber down off his stool. Then Sideswipe led the way back across the club, the two of them still holding hands.

When they got close enough, Sunstreaker stared at his brother’s face, reassured by the smile that Sideswipe gave him. It was echoed by Rung when he sat on the bench opposite Sunstreaker.

“Sunstreaker,” Rung said, his voice raised slightly to be heard over the music. “You never told me you had a brother.”

“You never told me you came to places like this,” Sunstreaker said, gesturing towards the ceiling.

Rung inclined his head as Sideswipe slid in next to Sunstreaker. Under the table, he placed a hand on Sunstreaker’s thigh, gently stroking the plating.

“Fair enough. So tell me… how would you like this evening to go? Sideswipe gave me an idea, but I would love to hear it directly from you. What do you like?”

Sideswipe reassuringly squeezed Sunstreaker’s knee and Sunstreaker leaned forward, his fuel pump beating excitedly. His brother was once more at his side, warm and supportive, and he was finally back home. Rung was like the sprinkles on top of a delectable oil cake and for once, Sunstreaker was going to indulge with no regrets.

\--

Rung didn’t have too many expectations when he entered Solace’s. A drink or two, maybe some conversation if someone was up for it, but he didn’t actually plan on leaving with anyone. So, he remained at the bar, rebuffing the advances that so far were a bit too forward. Just when he was about to call it a night and head back to the ship, someone leaned in on his right, gently brushing fingers against his shoulder.

“Hey, there. You’re Rung, aren’t you?”

Rung looked up in surprise, not recognizing the voice. He didn’t recognize the mech either, so it was a bit of a shock for a complete stranger to know his name.

“Yes. And you are?” he asked warily.

“Designation’s Sideswipe. I’m Sunstreaker’s brother. He probably hasn’t mentioned me, but we’re here together.” Sideswipe pointed across the room and Rung followed his gaze to see a darkened booth that did little to hide Sunstreaker’s distinctive gold color.

“He has not mentioned you, but he generally keeps to himself,” Rung replied, returning his attention to the mech lounging so carelessly against the bar’s edge. He acted completely at ease, but there was a coiled tension to him that suggested his occupation during the war had likely been similar to his brother’s. There was also a dark gleam to his optics that promised certain things if the right person knew to ask.

Sideswipe made a face. “Yeah, that’s not surprising. He got all the social anxiety, and I’m the social butterfly. Which is kind of funny once you get to know us a little better.”

Rung startled and drew back a little, starting to see the similarities between the brothers’ frames now that he looked closer. “… twins?”

“Yup, fraternal. Makes longer separations like we’ve had far more bearable than if we were split-sparks,” Sideswipe replied, nodding.

“I see. How can I help you exactly?” Rung asked, curious now.

“Well, thought I might enlist the assistance of a cute nerd like yourself to properly welcome him home. And by welcome him home, I mean overload him again and again until he can’t walk straight,” Sideswipe said, gently poking at Rung’s arm with one pinkie finger. He smiled winningly and Rung felt himself flush. He’d had one and a half drinks tonight, but he didn’t think that was the cause. No, not when one of his kinks was blunt honesty from his partners.

“You do not know that I’m a nerd,” Rung retorted, tilting his head down slightly. He looked up at Sideswipe through coyly lowered optic shutters. “Do not believe whatever Sunstreaker told you.”

“I tend to believe what I see. And what I’m seeing tells me you could take him to task perfectly. He’s easy, really; he’ll test you at first, but he gives in pretty quickly,” Sideswipe said, his voice turning sultry. Almost against his will, Rung found himself leaning forward, eagerly listening to what Sideswipe had to say.

“And what would _you_ be doing?” Rung asked archly. “Or would you be depositing your brother on my lap and leaving?”

“Me? I want to watch. Maybe give a suggestion or two, just based on our history, but mostly I want to observe a master at work,” Sideswipe said, gaze traveling down Rung’s frame like a light caress.

Rung considered the mech in front of him for a moment. He was saying all the right things and exhibiting the normal body language, but… “Are you attracted to me?”

Sideswipe tilted his head to the side, his confident smile faltering just slightly. “Is my answer a deal breaker?”

“No. I’m just curious,” Rung said. He had had millennia of observations to fall back on and something about Sideswipe’s demeanor was just a touch off. He had a suspicion, but he wanted to see if Sideswipe would lie or not.

“Then… kind of? I need at least a small bit of emotional connection before I can be physically attracted to someone, but I like the _potential_ of what you can do. And Sunstreaker wants you, so…”

Sideswipe trailed off and Rung nodded thoughtfully, his hunch confirmed. “Thank you for answering honestly. But you seem to be under the impression that I am used to dominating others and would be up to doing so to Sunstreaker. How did you come by this conclusion?”

“Well, you’re here, so I assumed you were into the scene. As to you favoring topping… I guessed.”

Rung blinked at Sideswipe, nonplussed. “You guessed?”

Sideswipe shrugged nonchalantly. “Yeah. The way you hold yourself, the look in your optics. Sunstreaker responds to you, although he couldn’t pinpoint why. It’s how you talk too – you choose each word so carefully although I suppose that could be from your job. That actually _is_ kind of hot to me by the way. So… am I wrong?”

Rung stared at Sideswipe incredulously before chuckling. Apparently Rung wasn’t the only one who routinely relied upon previous observations and instinct. “You are not.”

“Well, then, what do you say? I promise you, Sunny’s got a great mouth – now’s your chance to direct him to use it however you want. And any other part of him you’d like,” Sideswipe said with an enticing lilt to his voice. 

The whole proposition was tempting, honestly. There was a certain illicit thrill of going home with a stranger, but that hadn’t really appealed to Rung tonight. This way at least, he knew one of the mechs he would be accompanying. Sunstreaker was handsome, had always been polite to him, and apparently liked subservience. They didn’t move in the same social circles, but honestly, Sunstreaker didn’t have much of a social circle to begin with.

And neither did Rung.

“I’d like to talk to him in more detail first,” Rung said finally, downing the last of his drink.

“Of course. We can do a little planning session here and then go back to our apartment. Or rent a room, whichever you’d prefer,” Sideswipe said, holding out a hand when Rung slid to the edge of his stool, pedes dangling high about the floor. “We could go back to the ship too, I suppose, although I don’t know if you want any of your shippmates knowing your business.”

Rung took Sideswipe’s hand as support as he jumped down to the ground. “Perhaps a room. Neutral territory,” he said.

“Sure.”

Sideswipe kept hold of Rung’s hand, a light grip that Rung could break at any time, and led him back across the room. As he neared the booth, he saw Sunstreaker fidgeting in what Rung assumed was nervousness. He relaxed slightly when he glanced at Sideswipe’s face and once his brother slid in next to him, the tension disappeared completely, and he watched Rung with an eager expression.

“Sunstreaker… you never told me you had a brother,” Rung commented idly, surveying Sunstreaker in a new light. This promised to be an evening even better than he had originally imagined.

He couldn’t wait to get started.

~ End

**Author's Note:**

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